To a solution of 77 (194.9 mg, 0.560 mmol) and THF (5.6 mL) cooled to 0° C. was added phthalimide (90.70 mg, 0.616 mmol) and Ph3P (191.1 mg, 0.729 mmol). The reaction mixture was then treated with DEAD (331.8 μL, 0.729 mmol) and warmed to RT and stirred for 16 h. The reaction mixture was concentrated in vacuo. The crude product was purified by SiO2 Biotage chromatography eluting with hexanes/acetone to afford 238.5 mg (89.2%) of tert-butyl 3-((3-chloro-4-fluorophenyl)(1,3-dioxoisoindolin-2-yl)methyl)-3-fluoropyrrolidine-1-carboxylate (79): LC/MS: [M+1-100] m/z 377.0, 379.0.
